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Well I've always thought this section needed a good tutorial/general info thread on how scanners work and how to build one. So hopefully with some revisions I can get this thread to be a useful resource for those who want to get started in a lasershow system.
First thing - basic overview:
The heart of a lasershow system is the galvanometer system (galvos) Two mirrors are moved by high speed motors (one for each axis) so that the laser beam can be steered to any point within the scanning angle of the galvos. Galvos are usually 0-5v (single ended) or -5v to 5v if they are differential signal galvos. The voltage given to the galvo correlates to the angle of the mirror. The larger the voltage signal given, the larger the deflection angle of the mirror.
RGY/RGB/RGV systems:
Multiple color systems are made by combining the beams of two or more lasers using special mirrors called dichros that reflect certain colors of light while allowing other colors to pass through.
TTL Vs. Analog Modulation:
Modulation is a function of a laser to be able to be switched on and off by an external signal input. TTL modulation only has two possible states - on and off. Analog modulation is completely variable from no light output to full power. Analog modulation is preferred as it allows an infinite number of color combinations. Modulation signals are typically 0-5v.
Putting it all together, DACs and electrical theory:
The DAC (digital to analog converter) is what drives the lasershow system. The DAC takes digital data from the computer running the lasershow and outputs voltage signals to drive the galvos and modulate the lasers.
Examples:
Audio Card DAC
Pangolin
Mamba
First thing - basic overview:
The heart of a lasershow system is the galvanometer system (galvos) Two mirrors are moved by high speed motors (one for each axis) so that the laser beam can be steered to any point within the scanning angle of the galvos. Galvos are usually 0-5v (single ended) or -5v to 5v if they are differential signal galvos. The voltage given to the galvo correlates to the angle of the mirror. The larger the voltage signal given, the larger the deflection angle of the mirror.
RGY/RGB/RGV systems:
Multiple color systems are made by combining the beams of two or more lasers using special mirrors called dichros that reflect certain colors of light while allowing other colors to pass through.
TTL Vs. Analog Modulation:
Modulation is a function of a laser to be able to be switched on and off by an external signal input. TTL modulation only has two possible states - on and off. Analog modulation is completely variable from no light output to full power. Analog modulation is preferred as it allows an infinite number of color combinations. Modulation signals are typically 0-5v.
Putting it all together, DACs and electrical theory:
The DAC (digital to analog converter) is what drives the lasershow system. The DAC takes digital data from the computer running the lasershow and outputs voltage signals to drive the galvos and modulate the lasers.
Examples:
Audio Card DAC
Pangolin
Mamba
